The present invention relates to a snap terminal, and more particularly to a snap terminal having a generally annular standoff extending downwardly from its base to form an improved connection between the terminal and a component.
Electrical terminals must be connected to certain articles of manufacture to allow for the flow of electricity from one medium to a different medium. This is particularly true in instances where the conductive elements are embedded in a non-conductive material, such as glass or dielectric substrate. In, for instance, automotive glass panels having electrical wiring embedded therein for the purpose of defogging the window, electrical terminals must be attached to the glass panels to provide a point of connection for electrical current input and output.
Snap terminals are sometimes employed in this fashion. Snap terminals are generally two-piece terminals which are arranged in a mating configuration. Each of the terminals is electrically and mechanically connected to a component and the snap terminal components are then mated to form a releasable electrical and/or mechanical connection between the components. Snap terminals are commonly provided on 9-volt batteries.
The second type of snap terminal is formed by xe2x80x9ccrimping.xe2x80x9d A snap terminal formed by the xe2x80x9ccrimpingxe2x80x9d method joins two pieces: a hat-shaped base and a circular solder disc. The base used has a circular top wall, a vertical wall extending downwardly therefrom, and an annular flange. The solder disc which is joined to the base has, however, a diameter that is larger than that of the annular flange. The solder disc is placed substantially concentric to the annular flange, and the solder at the periphery of the disc is wrapped around the annular flange and crimped into place. In use, sufficient heat is applied to the terminal to melt the solder and adhere the terminal to a component.
The use of standoffs for soldering planar terminals is taught in U.S. Pat. No. 4,246,467 for extending a substantial portion of the terminal base in a spaced but substantially parallel plane with respect to a component. The result is the creation of an offset spacing for the solder to fill. The spacing defines a minimum volume between the terminal and the component in an attempt to create a uniform solder connection. U.S. Pat. Nos. 6,039,616 and 6,249,966 disclose the use of such standoffs with circular electrical terminals. However, the conditions present in many soldering applications render the creation of a uniform solder fillet difficult, if not impossible, regardless of the use of standoffs as taught by the prior art.
Environmental considerations are requiring the use of lead-free solder alloys. The use of lead-free solder increase the solder""s liquidus temperature 31%, with up to 94% less modules of elasticity for the new solder alloy. This makes having the most uniform solder fillet possible essential. Almost all of the automotive glass manufactured today is curved for design and aerodynamic considerations. This makes it difficult to solder because the terminal location is usually on an angle, and the effect of gravity on the molten solder can cause it to collect on the downward slope of the surface inside the hollow snap, where it forms an undetected irregular solder fillet that mechanically weakens the soldered connection.
Accordingly, what is needed is a snap terminal having a standoff that provides a space between the terminal and the component to define a minimum volume in which a solderable material can flow and further serves as a barrier to prevent additional solderable material from flowing into the hollow portion of the snap and forming an irregular solder fillet.
A male snap terminal is described which includes a base having a top wall, a vertical wall, an annular flange, and an annular standoff, which extends downwardly therefrom. The standoff defines an open space between the annular flange and a component when the terminal is positioned closely adjacent the component. The open space provides a minimum volume for receiving solderable material when the terminal is soldered to the component. The standoff is positioned concentric to the open portion of the snap terminal so that the standoff will serve as a barrier to substantially prevent excess solderable material from flowing into the open portion of the terminal and creating an irregular solder fillet therein.
It is therefore a principal object of the invention to provide a snap terminal having a generally annular standoff that provides a minimum volume for receiving solderable material when the terminal is positioned closely adjacent a component to which it is to be soldered.
Yet another object of the invention is to provide a snap terminal having a standoff that prevents excess solderable material from flowing into the open portion of the terminal when the terminal is soldered to a component.
Still another object of the present invention is to provide a snap terminal that is formed of one-piece unitary construction with an annular standoff, which prevents excess solderable material from flowing into the open portion of the terminal when the terminal is soldered to a component.
These and other objects will be apparent to those skilled in the art.